Construction machinery

ABSTRACT

The present invention relates to a construction machine, which is equipped with an engine ( 22 ), a first cooling unit group (R) consisting of a plurality of cooling units, and a second cooling unit group (R 1 ) where some cooling units in the first cooling unit group (R) are disposed in parallel. The remaining cooling unit (RN) of the first cooling unit group (R) is disposed with a gap (D) between itself and the second cooling unit group (R 1 ), or is disposed in parallel with the second cooling unit group (R 1 ). The construction machine is further equipped with a cooling fan ( 20 ) disposed so that it faces the cooling units disposed as described above. With this arrangement, the construction machine is capable of easily cleaning the cooling units, enhancing the cooling efficiency, and reducing the leakage of noise from the machine to the outside.

FIELD OF THE INVENTION

[0001] The present invention relates to a construction machine equippedwith an engine and a plurality of cooling units, in which some of thecooling units are disposed in parallel and cooled with a single coolingfan in order to enhance the cooling efficiency, reduce the leakage ofoperation noise, and facilitate the cooling of the cooling units.

BACKGROUND ART

[0002] Construction machines include, for example, a hydraulic shovelthat performs a digging operation for a dam, a tunnel, a road, watersupply and drainage, etc., or a dismantling operation for constructions,etc.

[0003] The hydraulic shovel is constructed of a lower travel body, anupper swivel body supported on the lower travel body so that it canswivel, and a working unit provided on the front portion of the upperswivel body.

[0004] The upper swivel body is usually provided with a driver's cab.However, there are cases where small hydraulic shovels have not adriver's cab but a driver's seat.

[0005] Furthermore, the frame of the swivel body is provided with anengine, a hydraulic pump, cooling units, batteries, control valves, afuel tank, a working-oil tank, etc.

[0006] The construction machine performs various operations such astraveling by the lower travel body, swiveling by the upper swivel body,digging by the working unit, etc. These operations are performed by ahydraulic actuator, constructed of a hydraulic motor, a hydrauliccylinder, etc. As shown in FIG. 11, pressure oil is supplied to thehydraulic actuator by the hydraulic pump 05 that is driven by the engine03.

[0007] In addition, units, such as the engine 03, radiator 06, hydraulicpump 05, and direction-switching valves for switching the direction ofthe pressure oil supplied from the hydraulic pump 05, are disposedwithin the upper swivel body.

[0008] The upper swivel body is provided with an engine room 02 having acover 01. Within the engine room 02, the engine 03 is provided, and theradiator 06 for cooling the engine 03, an oil cooler 010 for coolingworking oil, an intercooler 08 for cooling air which is supplied to thecombustion chamber of the engine 03, and a condenser 012, are disposed.

[0009] The intercooler 08, oil cooler 010, radiator 06, and condenser012 constitute a first cooling unit group R which is used to coolworking oil and cooling water. To expose the first cooling unit group Rto cooling air and then cool the coolants of the first cooling unitgroup R, a cooling fan 014 is disposed. The cooling fan 014 is driven bythe engine 03.

[0010] The cover 01 that constitutes part of the engine room 02 isprovided with outside-air introducing ports 01 a for introducing theoutside air, and exhaust ports 01 b for discharging the introduced air.The introduced air cools the first cooling unit group Rand then theengine 03, the hydraulic pump 05, and the direction switching valves.Thereafter, the air that has reached high temperature is discharged fromthe exhaust ports 01 b to the outside.

[0011] With this arrangement, cooling air is introduced through theoutside-air introducing ports 01 a. Within the engine room 02, a flow ofair occurs as indicated by arrows, cools the engine 02, the hydraulicpump 05, the direction switching valves, etc., and is discharged fromthe exhaust ports 01 b.

[0012] As shown in FIG. 11, with respect to the first cooling unit groupR provided within the engine room 02, the cooling air flows in the orderof condenser 012, intercooler 08, oil cooler 010, and radiator 06 fromthe upstream side.

[0013] The intercooler 08 is used for cooling air compressed by asupercharger 016 that increases the pressure of the fuel-air mixture inthe engine 03. Because of this, a filter unit 017 is provided on theexterior of the engine room 02 to prevent the entry of dust and dirt.

[0014] The supercharger 016 is used to compress introduced air byrotating the turbine with the energy of the exhaust gas of the engine03. Since the temperature of the introduced air rises due to adiabaticcompression, it is necessary to cool the introduced air before it issupplied to the engine 03, for the output of the engine 03 andpurification of the exhaust gas.

[0015] The introduced air is cooled by the intercooler 08, and isgenerally cooled to about 40 to 70° C. at the normal temperature.

[0016] Since the coolant of the intercooler 08 has to be cooled to atemperature lower than those of other heat exchangers, and the quantityof the radiant heat of the oil cooler 010 and the radiator 06 isrelatively large, the intercooler 08 is generally disposed on the mostupstream side of a flow of air, or on the upstream side from theradiator 06.

[0017] Since the supercharger 016 must be disposed on a portion of theengine 03, conduits 018, 019 for circulating compressed air areconnected between the supercharger 016 and the intercooler 08 andbetween the intercooler 08 and the engine 03.

[0018] For the aforementioned reasons, the aforementioned heat exchangeis performed in the order of condenser 12, intercooler 08, oil cooler010, and radiator 06, and in order to enhance the cooling efficiency,the condenser 12, the intercooler 08, the oil cooler 010, and theradiator 06 are disposed in close proximity to one another. However, inconstruction fields, dust and dirt tend to adhere to the condenser 012,the intercooler 08, the oil cooler 010, and the radiator 06. If dust anddirt adhere to the condenser 012, the intercooler 08, the oil cooler010, and the radiator 06, the aforementioned various operations cannotbe continued unless they are frequently cleaned.

[0019] In the case where the intercooler 08, the oil cooler 010, and theradiator 06 are disposed in the recited order, there are cases where, ina narrow space within the engine room 02 of the hydraulic shovel,particularly a narrow space within the engine room of a small hydraulicshovel, rotation of the oil cooler 010 becomes difficult. In the casewhere the intercooler 08 is disposed so as to face the oil cooler 010 orradiator 06, the intercooler 08 becomes a hindrance and therefore theoil cooler 010 cannot be cleaned.

[0020] Hence, the radiator 06 or oil cooler 010 is made of a lightweightaluminum alloy so that it can be easily lifted upward. The radiator 06or oil cooler 010 is first lifted upward to form an open space behindthe intercooler 08. Then, the intercooler 08 is cleaned, for example,with an air jet nozzle. The removed radiator 06 or oil cooler 010 isalso cleaned, and is returned to the original position.

[0021] Because the air suction and exhaust tubes of the intercooler 08are large in diameter and are generally fixed on the upper swivel body,the aforementioned operation becomes necessary.

[0022] In addition, in the conventional construction machine shown inFIG. 11, the first cooling unit group R, the engine 03, and thehydraulic pump 05 are disposed in a cooling-air passage which is widelycommunicated through a core having the area of the wide cooling-airpassage of the cooling units within the engine room 02. Therefore, thereis a fear that noise generated by the engine 03 and the cooling fan 014will be transmitted from the wide area to the outside.

[0023] In the conventional construction machine, if the first coolingunit group R is not cleaned, the cooling fan 014 will be clogged by dustand dirt. As a result, the circulation of the cooling air for the firstcooling unit group R is reduced and the cooling efficiency becomes low.Because of this, the performance of the construction machine cannot besufficiently utilized. In addition, to clean the radiator 06 or oilcooler 010, removing and installing the radiator 06 or oil cooler 010require labor and time, resulting in a reduction in the operationefficiency. Furthermore, as described above, there is a fear that noisewill be transmitted to the outside of the construction machine.

[0024] The present invention has been made in view of the problemsmentioned above. Accordingly, it is the primary object of the presentinvention to provide a construction machine that is capable of easilycleaning the cooling units, enhancing the cooling efficiency, andreducing noise. The construction machine is equipped with a firstcooling unit group consisting of a plurality of cooling units, and asecond cooling unit group where some cooling units in the first coolingunit group are disposed in parallel. The remaining cooling unit of thefirst cooling unit group is disposed with a gap between itself and thesecond cooling unit group, or is disposed in parallel with the secondcooling unit group. The construction machine is further equipped with acooling fan disposed so that it faces the cooling units disposed asdescribed above.

DISCLOSURE OF THE INVENTION

[0025] To achieve the object of the present invention mentioned above,there is provided a first construction machine comprising: a nearlysealed engine room section where an engine is disposed; a first coolingunit group comprising a plurality of cooling units; and a single coolingfan for cooling a second cooling unit group where some cooling units ofthe first cooling unit group are disposed in parallel; wherein thesecond cooling unit group and the cooling fan are disposed so that theyface each other.

[0026] With this arrangement, cleaning of the cooling units can beeasily performed and the cooling efficiency can be enhanced. Inaddition, the leakage of engine noise can be reduced.

[0027] In accordance with the present invention, there is provided aconstruction machine comprising: a first cooling unit group comprising aplurality of cooling units; a cooling fan for cooling a second coolingunit group where some cooling units of the first cooling unit group aredisposed in parallel; an engine; a partition member provided between thecooling fan and the engine; a chamber, partitioned and formed by thepartition member, where the first cooling unit group and the cooling fanare disposed; and a nearly sealed engine room section, partitioned bythe partition member, where the engine is disposed; wherein the coolingfan comprises a single cooling fan.

[0028] With this arrangement, cleaning of the cooling units can beeasily performed. In addition, the leakage of engine noise can bereduced and the cooling efficiency can be enhanced.

[0029] In the first and second construction machines of the presentinvention, the second cooling unit group and the remaining cooling unitof the first cooling unit group are disposed so that they face eachother. With this arrangement, the whole of the cooling units can be madecompact. In addition, the cooling efficiency can be enhanced with thesingle cooling fan, and the operation cost can be reduced.

[0030] In the construction machines of the present invention, a gap isprovided between the second cooling unit group and the remaining coolingunit so that cleaning can be performed. With this arrangement, dust anddirt on the cooling units can be easily cleaned, for example, byinserting an air jet nozzle into the gap.

[0031] In the construction machines of the present invention, agap-closing cover is provided to nearly close at least the circumferenceof the gap and is rotatable or detachable. This can prevent a reductionin the cooling efficiency due to the leakage of the cooling air from thegap. In the case where the rotatable or detachable gap-closing cover isused, the cooling efficiency can be enhanced. In addition, in cleaningthe cooling units, the rotatable or detachable gap-closing cover isrotated or removed, and dust and dirt on the cooling unit can be easilycleaned, for example, by inserting an air jet nozzle into the gap.

[0032] In the construction machines of the present invention, the gap Dbetween the second cooling unit group and the remaining cooling unit ofthe first cooling unit group disposed so as to face the second coolingunit group is set so that a ratio of the gap D to a height H of acooling unit of the second cooling unit group on the upstream side ofthe remaining cooling unit is D/H=0.05 to 0.3. With the ratio D/H, adegree of freedom in designing the gap D and the height H can beincreased and the gap D and the height H can be suitably disposedaccording to design specification.

[0033] In the first and second construction machines of the presentinvention, the gap D is set to about 30 to 300 mm, preferably about 40to 100 mm. Because of this, there is an effect that the cooling unitscan be easily set according to design specification by the gap D.

[0034] In the construction machines of the present invention, thecooling unit of the second cooling unit group on the upstream side ofthe remaining cooling unit comprises an intercooler. This makes itpossible to easily perform cleaning of the cooling units including theintercooler.

[0035] In the construction machine of the present invention, the nearlysealed engine room section is constructed so that cooling air introducedby the cooling fan is drawn in, or is constructed so that it isventilated by discharging the cooling air within the nearly sealedengine room section, which has risen in temperature, from blowoff boresof the partition member with the cooling air introduced by the coolingfan.

[0036] With this construction, the leakage of noise from the engine tothe outside can be effectively reduced.

[0037] In the first and second construction machines of the presentinvention, the cooling fan comprises an axial flow fan, a bent axis flowfan, or a centrifugal fan. Therefore, by suitably using an axial flowfan, a bent axis flow fan, or a centrifugal fan, the cooling efficiencycan be enhanced and the cooling fan can be made compact.

[0038] In the construction machines of the present invention, the nearlysealed engine room section is provided with an ejector. With theejector, cooling within the nearly sealed engine room section can beefficiently performed.

[0039] In the construction machines of the present invention, the nearlysealed engine room section is provided with an ejector and a ventilatingfan. The synergetic effect of the ejector and the ventilating fan canenhance the cooling effect within the nearly sealed engine room section.

[0040] The construction machine of the present invention furthercomprises cylindrical guide members which have a communicating borecorresponding and communicating with a communicating bore or blowoffbore provided in the partition member. The cylindrical guide membersmake it possible to enhance the cooling effect within the nearly sealedengine room section.

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention will be described in further detail withreference to the accompanying drawings wherein:

[0042]FIG. 1 is a diagrammatic side view showing a hydraulic shovel towhich a construction machine of a first embodiment of the presentinvention is applied;

[0043]FIG. 2 is a diagrammatic plan view taken along line 2A-2A in FIG.1;

[0044]FIG. 3 is a diagrammatic end elevational view taken in thedirection of arrow 3A in FIG. 2;

[0045]FIG. 4(A) is an enlarged perspective view showing the coolingunits shown in FIG. 3, the radiator being disposed so as to face the oilcooler and the intercooler, disposed in parallel in a verticaldirection;

[0046]FIG. 4(B) is an enlarged perspective view showing the state inwhich the oil cooler has been rotated so that the intercooler can becleaned;

[0047]FIG. 5 is an enlarged perspective view showing a firstmodification of the first embodiment shown in FIG. 4(A);

[0048]FIG. 6(A) is an enlarged perspective view showing a secondmodification of the first embodiment shown in FIG. 5, the radiator andthe oil cooler being disposed in parallel and the intercooler beingdisposed with a gap between itself and them;

[0049]FIG. 6(B) is an enlarged perspective view showing another exampleof the gap-closing cover shown in FIG. 6(A);

[0050]FIG. 6(C) is an enlarged perspective view showing the case wheretwo gap-closing covers are provided on the upper and lower portions ofthe intercooler;

[0051]FIG. 6(D) is an enlarged perspective view showing the case wherethe gap-closing cover is detachably provided on the top surface of theintercooler;

[0052]FIG. 7 is an enlarged perspective view showing a thirdmodification of the first embodiment shown in FIG. 6(A);

[0053]FIG. 8 is a diagrammatic plan view showing a construction machineaccording to a second embodiment of the present invention;

[0054]FIG. 9 is a diagrammatic end elevational view taken in thedirection of arrow 9A in FIG. 8;

[0055]FIG. 10 is a diagrammatic end elevational view showing aconstruction machine according to a third embodiment of the presentinvention; and

[0056]FIG. 11 is a vertical transverse sectional view showing the engineroom of a conventional hydraulic shovel.

BEST MODE FOR CARRYING OUT THE INVENTION

[0057] Embodiments of the present invention will hereinafter bedescribed with reference to the drawings.

[0058] (A) First Embodiment

[0059]FIG. 1 shows a hydraulic shovel to which a construction machine ofa first embodiment of the present invention is applied.

[0060] The hydraulic shovel P of the first embodiment of the presentinvention, as shown in FIG. 1, is constructed of an upper swivel body 2,a lower travel body 4, and a working unit 6.

[0061] The front end portion of the upper swivel body 2 is provided witha driver's cab 8, and the rear end portion is provided with acounterweight 10. Furthermore, a suction-type engine room 12, as shownin FIGS. 2 and 3, is provided on the frame of the upper swivel body 2and disposed in front of the counterweight 10 of the hydraulic shovel P.

[0062] Within this engine room 12, there is provided a first coolingunit group R, which consists of an intercooler 14, an oil cooler 16, anda radiator 18.

[0063] The oil cooler 16 and the intercooler 14 in the first coolingunit group R are disposed in parallel in a vertical direction andconstitute a second cooling unit group R1. The radiator 18, which is theremaining cooling unit RN of the first cooling unit group R, is disposedon the downstream side of the second cooling unit group R1. The oilcooler 16 is disposed in close proximity to the upper portion of theradiator 18. The intercooler 14 is disposed in close proximity to thelower portion of the oil cooler 16 with the gap D between theintercooler 14 and the radiator 18, determined by design specification.

[0064] In addition, as shown in FIGS. 2 and 3, a single cooling fan 20is provided on the downstream side of the first cooling unit group Rdisposed within the engine room 12 and is used to cool the first coolingunit group R.

[0065] Furthermore, an engine 22 and a hydraulic pump 24 connected tothe engine 22 are provided behind the cooling fan 20. Between the engine22 and the hydraulic pump 24, there is provided a partition plate DW.

[0066] A partition member 26 is provided between the cooling fan 20 andthe engine 22. Within a chamber 28 partitioned and formed by thepartition member 26, the first cooling unit group R and the cooling fan20 are disposed. Within a nearly sealed engine room section 30,partitioned by the partition member 26 and nearly sealed, the engine 22and the hydraulic pump 24 are disposed. The aforementioned secondcooling unit group R1 (the intercooler 14 and the oil cooler 17 in thefirst embodiment) and the remaining cooling unit RN (the radiator 18 inthe first embodiment) of the first cooling unit group R are disposed soas to face each other, and are cooled by the single cooling fan 20.

[0067] A plurality of guide members 26R are provided on the downstreamside of the partition member 26 (back surface of the partition member26). Each guide member 26R is formed in cylindrical form by guide pieces26R1, 26R2 provided around a communicating bore 26 a formed in thepartition member 26. In the first embodiment, the guide member 26R issquare in cross section.

[0068] This guide member 26R has at least the size of the communicatingbore 26 a formed in the partition member 26. It is preferable that theguide member 26R be a communicating bore larger than the communicatingbore 26 a.

[0069] In the case where a supercharger 32 is provided in the engine 22,as shown in FIG. 3, conduits 34, 36 for circulating compressed air areconnected between the supercharger 32 and the intercooler 14 and betweenthe intercooler 14 and the engine 22, respectively. The conduits 34, 36penetrate the partition member 26, the radially outer portion of theradiator 18, and a partition plate 18 a. The partition plate 18 a isprovided between an upper partition wall (engine hood) Wa, a frontpartition wall Wb, a rear partition wall Wc, and a bottom partition wallWd which constitute a cover 1. The cover 1 constitutes the engine room12. The cover 1 further has side partition walls Ws, Ws between thefront partition wall Wb and the rear partition wall Wc.

[0070] A muffler 38 connected to an exhaust port is provided on the rearupper portion of the engine 22 so that exhaust gas is discharged fromthe engine 22 through an exhaust pipe 40. In addition, part of theexhaust gas is supplied to the supercharger 32 through an exhaust pipe32 a to drive the supercharger 32.

[0071] As shown in FIGS. 4(A) and 4(B), the oil cooler 16, for example,is constructed so that it is rotatable on a rotation axis AX through ahinge mechanism 44 provided between the oil cooler 16 and the radiator18 (or the upper swivel body 2). The conduits 17 a, 17 b of the oilcooler 16 are connected through rotatable tube fittings 21, 21. The tubefittings 21 are rotatable coaxially with the rotation axis AX andprovided on a working-oil supply side and a working-oil exhaust side.Therefore, even if the oil cooler 16 rotates, the conduits 17 a, 17 bare prevented from being twisted or damaged.

[0072] The suction-type nearly sealed engine room section 30 of thefirst embodiment is constructed as described above. Therefore, if theengine 22 and the cooling fan 20 are operated, cooling air is introducedthrough the outside-air introducing port 1 a of the cover 1 and thencools the first cooling unit group R. Thereafter, the cooling air passesthrough the communicating bores 26 a of the partition member 26 andthrough the guide members 26R, is introduced into the nearly sealedengine room section 30, and cools the engine 22, the muffler 38, etc.After that, the cooling air is discharged from an exhaust port 1 bprovided on the cover 1.

[0073] In this manner, the radiator 18, the oil cooler 16, and theintercooler 14 are efficiently cooled with the single cooling fan 20.However, cleaning of the first cooling unit group R must be frequentlyperformed. For example, particularly, in a construction site wheredismantling of a structure is performed, cleaning of the first coolingunit group R must be performed every day, or a plurality of times a dayas occasion demands.

[0074] In performing the above-mentioned cleaning operation, theconstruction of the first cooling unit group R of the first embodimentis useful.

[0075] That is, the oil cooler 16 of the second cooling unit group R1(oil cooler 16 and intercooler 14) of the first cooling unit group R(radiator 18, oil cooler 16, and intercooler 14) is rotatable as shownin FIG. 4(B) through the hinge mechanism 44 with respect to theremaining cooling unit RN (radiator 18) of the first cooling unit groupR so that an open space can be formed above the top surface of theintercooler 14. Therefore, the intercooler 14 and the radiator 18 can beeasily cleaned by inserting an air jet nozzle into the gap between theradiator 18 and the intercooler 14 and then jetting air. Similarly, theoil cooler 16 and the radiator 18 in the open states can be easilycleaned with a jet of air.

[0076] After the cleaning, the oil cooler 16 is returned to its originalposition, as shown in FIG. 4(A). The oil cooler 16 can be easily anddetachably fastened by engaging thumbscrews 48 a with the engaging bolt48 of a hinge mechanism 46 that is used as a stopper member providedbetween the oil cooler 16 and the intercooler 14.

[0077] The gap D between the intercooler 14 and at least one coolingunit (radiator 18 in the first embodiment) of the first cooling unitgroup R is suitably determined by design specification. For instance,the gap D is determined so that a ratio of D/H becomes about 0.05 to0.3. The letter H in the ratio of D/H represents the height of theintercooler 14 that faces at least one cooling unit (radiator 18 in thefirst embodiment) of the first cooling unit group R.

[0078] The gap D is usually set to about 30 to 200 mm. In the case oflarge machine types and special machine types, the gape D is set toabout 30 to 300 mm. It is preferable that the gap D be set to about 40to 100 mm.

[0079] In the first embodiment, the intercooler 14 is disposed so thatit faces one cooling unit of the first cooling unit group R. However,the cooling unit that faces one cooling unit of the first cooling unitgroup R is not limited to the intercooler 14. In the case where twoother cooling units in the first cooling unit group R are disposed sothat they face each other, the same effect as the first embodiment canbe obtained, if the aforementioned gap D is provided between the twocooling units.

[0080] Next, a first modification of the first embodiment shown in FIG.4 will be described with reference to FIG. 5. The same referencenumerals will be applied to practically the same parts as the firstembodiment, and a description will be given of points differing from thefirst embodiment.

[0081] In the first modification, with the gap D between the radiator 18of the second cooling unit group R1 (oil cooler 16 and radiator 18) andthe remaining cooling unit RN (intercooler 14) of the first cooling unitgroup R (oil cooler 16, radiator 18, and intercooler 14), the remainingcooling unit RN (intercooler 14) of the first cooling unit group R isdisposed as shown in FIG. 5. Furthermore, a condenser 19 for an airconditioner is disposed with the gap D between itself and the oil cooler16.

[0082] As with the first embodiment, cooling can be performed with thesingle cooling fan 20. Therefore, the operation costs can be reduced. Inaddition, cleaning can be easily performed by inserting theaforementioned air jet nozzle into the gap D between the intercooler 14and the radiator 18 and the gap D between the oil cooler 16 and thecondenser 19 and then jetting air. Therefore, the operation efficiencycan be enhanced.

[0083] Next, a second modification of the first embodiment shown in FIG.5 will be described with reference to FIG. 6. The same referencenumerals will be applied to practically the same parts as the firstembodiment, and a description will be given of points differing from thefirst embodiment.

[0084] In the second modification, with the gap D between the secondcooling unit group R1 (oil cooler 16 and radiator 18) and the remainingcooling unit RN (intercooler 14) of the first cooling unit group R (oilcooler 16, radiator 18, and intercooler 14), the remaining cooling unitRN (intercooler 14) of the first cooling unit group R is disposed asshown in FIG. 6(A).

[0085] As with the first embodiment, cooling can be performed with thesingle cooling fan 20. Therefore, the operation costs can be reduced. Inaddition, cleaning can be easily performed by inserting theaforementioned air jet nozzle into the gap D between the second coolingunit group R1 (oil cooler 16 and radiator 18) and the remaining coolingunit RN (intercooler 14) and then jetting air. Therefore, the operationefficiency can be enhanced.

[0086] In the first embodiment and the first and second modificationsshown in FIGS. 2 to 6(A), if gap-closing covers CV are provided tonearly close at least the circumference of the gap D shown in FIG. 6(A),or if rotatable or detachable gap-closing covers CV of elastic materialare provided along the perimeter of the intercooler 14 so that they aredetachable or rotatable with female screws 48 a, a reduction in thecooling efficiency due to the leakage of cooling air from the gap D canbe prevented.

[0087] In the case where rotatable or detachable gap-closing covers CVare provided, the cooling efficiency can be enhanced. In addition, ifthe rotatable or detachable gap-closing covers CV are rotated or removedwhen cleaning is performed, dust and dirt on the cooling units can beeasily cleaned, for example, by inserting an air jet nozzle into the gapD.

[0088] Other examples of the mounting structure for the gap-closingcover CV shown in FIG. 6(A) will be described with reference to FIGS.6(B) to 6(D).

[0089] In the example shown in FIG. 6(B), brackets RS2 extend from aframe RS1 attached to the radiator 18 and the oil cooler 16 and areattached to the intercooler 14. One end of a gap-closing cover CV isrotatably attached to the frame RS1 through hinges CVh, while the otherend is detachably attached to the intercooler 14 by thumbscrews 48 a. Inthis way, a plurality of gap-closing covers CV are disposed along theouter perimeter of the intercooler 14 so that the aforementioned gap Dis closed.

[0090] In the example of FIG. 6(C), the aforementioned gap-closingcovers CV are provided on the top surface and bottom surface of theintercooler 14. This structure is employed when the aforementioned gap Dis small. In this case, cost reduction can be achieved.

[0091] In the example of FIG. 6(D), the aforementioned gap-closingcovers CV are detachably attached to the outer perimeter of theintercooler 14 by thumbscrews 48 a so that the aforementioned gap D isclosed.

[0092] In addition, if the gap-closing covers CV described in FIG. 6 areprovided to close the gap D shown in FIGS. 2 to 5, the leakage of theaforementioned cooling air from the gap D will be prevented andtherefore the cooling efficiency can be enhanced.

[0093] Next, a third modification of the first embodiment shown in FIG.6(A) will be described with reference to FIG. 7. The same referencenumerals will be applied to practically the same parts as the firstembodiment, and a description will be given of points differing from thefirst embodiment.

[0094] In the third modification, the aforementioned second cooling unitgroup R1, in which some cooling units in the aforementioned firstcooling unit group R (intercooler 14, oil cooler 16, radiator 18, andcondenser 19) are disposed in parallel, consists of an intercooler 14,an oil cooler 16, and a radiator 18.

[0095] The remaining cooling unit (condenser 19) RN of the first coolingunit group R is provided on a suitable place on the second cooling unitgroup R1 disposed as shown in FIG. 6.

[0096] As with the first embodiment, the intercooler 14, the oil cooler16, and the radiator 18 can be cooled with the single cooling fan 20.Therefore, the operation costs can be reduced. In addition, theintercooler 14, the oil cooler 16, and the radiator 18 are individuallydisposed. Because of this, they can be easily cleaned by jetting airdirectly to them, without performing rotation and providing the gap D asin the aforementioned cases. Therefore, the operation efficiency can beenhanced.

[0097] (B) Second Embodiment

[0098] The second embodiment of the present invention will be describedwith reference to FIGS. 8 and 9. The same reference numerals will beapplied to practically the same parts as the first embodiment, and adescription will be given of points differing from the first embodiment.

[0099] The arrangement of the cooling units in the second embodiment isthe same as the first embodiment shown in FIG. 4. Therefore, the engineroom of the second embodiment constitutes a blowoff-type nearly sealedengine room section 30 a, as shown in FIGS. 8 and 9.

[0100] The partition member 26A of the nearly sealed engine room section30 a has a plurality of blowoff bores 26 b in the upper portion thereof,as shown in FIG. 9. The lower portion of the partition member 26A isformed into a non-bored portion 26 c. Therefore, the cooling air, whichhas been introduced through an outside-air introducing port 1 a byactuation of the cooling fan 20 and has cooled the first cooling unitgroup R, impinges on the non-bored portion 26 c of the partition member26A, then flows upward, and is discharged from an exhaust port 3 b.

[0101] The cooling air flowing upward flows along the front surface ofthe upper portion of the partition member 26A having the blowoff bores26 b, and generates a negative pressure region near the blowoff bores 26b. Because of the negative pressure, the cooling air within the nearlysealed engine room section 30 a that has reached high temperature ispassed through the blowoff bores 26 b, and is discharged from theexhaust port 3 b along with the cooling air that has cooled the firstcooling unit group R. Therefore, air within the nearly sealed engineroom section 30 a can be efficiently ventilated. In addition, if therear surface, on the engine side, of the partition member 26A areprovided with the guide members 26R as in the first embodiment shown inFIGS. 2 and 3, the ventilation efficiency can be further enhanced.

[0102] In the second embodiment, the nearly sealed engine room section30 a is provided with an ejector EJ, as shown in FIG. 9. Because of theejector EJ, the cooling effect within the nearly sealed engine roomsection 30 a can be enhanced and the leakage of noise generated in theengine 22 and hydraulic pump 24 within the nearly sealed engine roomsection 30 a can be reduced.

[0103] Now, a description will be given of the ejector EJ. In theexhaust system of the engine 22, a muffler 38 is connected to theexhaust tube 40 of the engine 22, and there is provided an upperpartition wall Wa (or an engine hood) which constitutes part of thecover 1 of the nearly sealed engine room section 30 a in which the exitport 40 a of the muffler 38 is disposed.

[0104] If the ejector EJ (which consists of an outer tube and an innertube to be described later and ejects the heated air within the nearlysealed engine room section 30 a to the outside by employing the exhaustpressure in the engine 22 that is discharged to the outside) is providedin part of the upper partition wall Wa, the nearly sealed engine roomsection 30 a, the engine 22, etc., can be more effectively cooled andthe cooling efficiency can be enhanced.

[0105] The ejector EJ is constructed of an exit port 40 a of an exhausttube (inner tube) 40 extending from the muffler 38; an ejector tube 40Awhich surrounds the exit port 40 a and extends from the upper partitionwall Wa beyond the exit port 40 a; and an ejector gap 40 c, formedbetween the exit port 40 a and the ejector tube 40A, which ejects airfrom the nearly sealed engine room section 30 a.

[0106] If the bottom partition wall Wd of the nearly sealed engine roomsection 30 a is provided with a plurality of slit intake ports S1 asneeded to facilitate the ventilation of the nearly sealed engine roomsection 30 a, the outside air introduced through the intake ports S1will flow as indicated by arrows EY and therefore the ejector EJ canenhance the cooling efficiency.

[0107] The intake ports S1 are equipped with louvers S, respectively.The louvers S constitute noise suppression means NS that suppresses theleakage of engine noise from the nearly sealed engine room section 30 ato the outside. As shown in FIG. 9, each louver S is formed by pullingup a plate portion which is left behind when cutting the bottompartition wall Wd to form the intake port S1.

[0108] If the noise suppression means NS is constructed so that theintake ports S1, formed into a box shape by a noise intercepting plateNSa, have a silencing effect and that the leakage of engine noise andintroduced-air sound from the intake ports S1 to the outside of thenearly sealed engine room section 30 a can be suppressed, the noisesuppression means NS can further reduce the aforementioned leakage ofnoise.

[0109] Since negative pressure occurs around the engine exhaust airejected from the exit port 40 a of the exhaust tube 40 of the engine 22,the pressure near the ejector gap 40 c becomes negative. Therefore, theair within the nearly sealed engine room section 30 a, along with heat,can be forcibly discharged to the outside by pump action caused by thenegative pressure.

[0110] Although not shown, a ventilating fan (e.g., an axial flow fan20K shown in FIGS. 8 and 10 and a sirocco fan 20Ks shown in FIG. 9),along with the ejector EJ, can be suitably disposed, for example, nearthe supercharger 32 or muffler 38 of the nearly sealed engine roomsection 30 a (which becomes a heat generation source) so thatventilation within the nearly sealed engine room section 30 a isfacilitated. In this case, the cooling efficiency can be furtherenhanced.

[0111] In the first and second embodiments, the partition member 26 or26A is provided to constitute the nearly sealed engine room section 30or 30 a, so the leakage of noise from the engine 22 and the hydraulicpump 24 to the outside can be reduced.

[0112] The first and second embodiments have been described withreference to the case of employing an axial flow fan. However, even ifvarious types of centrifugal fans and bent axis flow fans, including asirocco fan, are used, the same effect as the first and secondembodiments can be obtained.

[0113] (C) Third Embodiment

[0114] A description will be given of a third embodiment of the presentinvention using the above-mentioned sirocco fan.

[0115] For instance, instead of the axial flow fan 20 of the secondembodiment shown in FIG. 9, a sirocco fan 20 s is employed as shown inFIG. 10. The same reference numerals will be applied to practically thesame parts as the first and second embodiments, and a description willbe given of points differing from the first and second embodiments.

[0116] The third embodiment, as shown in FIG. 10, is equipped with theejector EJ described in the second embodiment of FIG. 9, but adescription will first be made on the assumption that it is not equippedwith the ejector EJ.

[0117] As shown in FIG. 10, the sirocco fan 20 s is disposed between apartition member 26A and a first cooling unit group Rand is driven bydrive means such as an engine 22, a hydraulic motor, an electric motor,etc. In addition to an exhaust port 3 b, the exhaust port 1 b describedin the first embodiment is provided.

[0118] In the third embodiment, a guide member g is provided near theouter periphery of the sirocco fan 20 s so that part of the cooling airfrom the sirocco fan 20 s is supplied to a nearly sealed engine roomsection 30 a through the communicating bores (suction bores) 26 a of thepartition member 26A. Therefore, part of the cooling air guided by theguide member g flows toward a muffler 38 and cools a supercharger 32.

[0119] In the third embodiment constructed as described above, if theengine 22 and the sirocco fan 20 s are operated, cooling air isintroduced through the outside-air introducing port 1 a of a cover 1 andthen cools the first cooling unit group R. Next, the cooling air flowsin the circumferential direction of the sirocco fan 20 s and isdischarged from the exhaust port 3 b. Furthermore, part of the coolingair guided by the guide member g cools the engine 22, the muffler 38,etc., and is discharged from the exhaust port 1 b.

[0120] In addition , if the sirocco fan 20 s is replaced with the axialflow fan 20 of the second embodiment shown in FIG. 9, the sameoperational effect as the second embodiment can be obtained.

[0121] Therefore, in the third embodiment, the efficiency of cooling thefirst cooling unit group R can be enhanced and the leakage of operationnoise from the engine 22, the hydraulic pump 24, etc., can be reduced bythe nearly sealed engine room section 30 a. Furthermore, since the firstcooling unit group R can be easily cooled, the operation rate of theabove-mentioned construction machine can be enhanced.

[0122] If the ejector EJ of the second embodiment is provided as shownin FIG. 10, there is no need to provide the exhaust port 1 b.Furthermore, both the ejector EJ and the exhaust port 1 b may bedisposed. Therefore, if the arrangement of the ejector EJ and theexhaust port 1 b is determined according to the aforementioned variousobjects by design specification, the aforementioned cooling, noisereduction, cleaning, etc., can be more effectively performed.

[0123] (D) Others

[0124] While the present invention has been described with reference tothe embodiments applied to a transverse engine, the invention is not tobe limited to the transverse engine, but may be modified within thescope of the invention hereinafter claimed. For example, in the casewhere the present invention is applied to a vertical engine, variouschanges may be made where appropriate. In addition, numerous changes maybe made according to changes in the conditions determined by designspecification, or according to machine specification, etc.

INDUSTRIAL APPLICABILITY

[0125] The construction machine of the present invention, as describedabove, is equipped with a first cooling unit group R consisting of aplurality of cooling units, and a second cooling unit group R1 wheresome cooling units of the first cooling unit group R are disposed inparallel. The remaining cooling unit of the first cooling unit group Ris disposed with a gap between itself and the second cooling unit groupR1, or is disposed in parallel with the second cooling unit group R1.The construction machine is further equipped with a cooling fan disposedso that it faces the cooling units disposed as described above. Withthis arrangement, cleaning, cooling, and noise reduction can beefficiently performed. Thus, the present invention is useful as aconstruction machine that is capable of easily cleaning the coolingunits, enhancing the cooling efficiency, and reducing noise.

1. A construction machine comprising: a nearly sealed engine roomsection (30, 30 a) where an engine (22) is disposed; a first coolingunit group (R) comprising a plurality of cooling units; and a singlecooling fan (20) for cooling a second cooling unit group (R1) where somecooling units of said first cooling unit group (R) are disposed inparallel; wherein said second cooling unit group (R1) and said coolingfan (20) are disposed so that they face each other.
 2. A constructionmachine comprising: a first cooling unit group (R) comprising aplurality of cooling units; a cooling fan (20) for cooling a secondcooling unit group (R1) where some cooling units of said first coolingunit group (R) are disposed in parallel; an engine (20); a partitionmember (26, 26A) provided between said cooling fan (20) and said engine(20); a chamber (28), partitioned and formed by said partition member(26, 26A), where said first cooling unit group (R) and said cooling fan(20) are disposed; and a nearly sealed engine room section (30, 30 a),partitioned by said partition member (26, 26A), where said engine (22)is disposed; wherein said cooling fan (20) comprises a single coolingfan (20).
 3. The construction machine as set forth in claim 1 or 2,wherein said second cooling unit group (R1) and the remaining coolingunit (RN) of said first cooling unit group (R) are disposed so that theyface each other.
 4. The construction machine as set forth in claim 3,wherein a gap (D) is provided between said second cooling unit group(R1) and said remaining cooling unit (RN) so that cleaning can beperformed.
 5. The construction machine as set forth in claim 4, whereina gap-closing cover (CV) is provided to nearly close at least thecircumference of said gap (D) and is rotatable or detachable.
 6. Theconstruction machine as set forth in any one of claims 1 through 5,wherein a gap (D) between said second cooling unit group (R1) and theremaining cooling unit (RN) of said first cooling unit group (R)disposed so as to face said second cooling unit group (R1) is set sothat a ratio of said gap (D) to a height (H) of a cooling unit of saidsecond cooling unit group (R1) on the upstream side of said remainingcooling unit (RN) is (D/H)=0.05 to 0.3.
 7. The construction machine asset forth in claim 6, wherein said gap (D) is set to about 30 to 300 mm,preferably about 40 to 100 mm.
 8. The construction machine as set forthin claim 6 or 7, wherein said cooling unit of said second cooling unitgroup (R1) on the upstream side of said remaining cooling unit (RN)comprises an intercooler (14).
 9. The construction machine as set forthin claim 2, 4, or 6, wherein said nearly sealed engine room section (30,30 a) is constructed so that cooling air introduced by said cooling fan(20) is drawn in, or is constructed so that it is ventilated bydischarging cooling air within said nearly sealed engine room section(30, 30 a), which has risen in temperature, from blow off bores (26 b)of said partition member (26, 26A) with cooling air introduced by saidcooling fan (20).
 10. The construction machine as set forth in claim 1,2, or 9, wherein said cooling fan (20) comprises an axial flow fan, abent axis flow fan, or a centrifugal fan.
 11. The construction machineas set forth in claim 1, 2, or 9, wherein said nearly sealed engine roomsection (30, 30 a) is provided with an ejector (EJ).
 12. Theconstruction machine as set forth in claim 1, 2, 9, or 11, wherein saidnearly sealed engine room section (30, 30 a) is provided with an ejector(EJ) and a ventilating fan (20K, 20Ks).
 13. The construction machine asset forth in claim 1, 2, 6, 7, 9, 11, or 12, further comprisingcylindrical guide members (26R) which have a communicating borecorresponding and communicating with a communicating bore (26 a) orblowoff bore (26 b) provided in said partition member (26, 26 a).